UK MICE meeting at RAL

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UK MICE meeting at RAL 3 March 2004 WP2 --
Stress behaviour at the Coil support
tube By Stephanie Yang, Oxford
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Aim of this exercise
Different coil support tube design have been
developed to improve its mechanical strength. The
aim of this exercise is to investigate how each
design behaves.
All the models are applied the same boundary
condition and loads. The material properties
used are the same.
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The three Coil support tube arrangements
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Details of the coil modelling
Unit cell
The coil consists of 81 x 109 cells
Coil Material properties Conductor
(orthotropic) Mass density 6520 kg /m3 Er
50 GPa Ez 70 GPa E? 90GPa Poissons Ratio
0.3 Insulation (fibre-glass) mass density 1270
kg/m3 E 3GPa Poissons Ratio 0.4 Epoxy Mass
density 1280 kg /m3 E 5000MPa Poissons Ratio
0.4
0.3 mm epoxy layer
Coil size 90 x 180 mm Coil support thickness
25mm
Focus Coil force data is from Jim Rochford (RAL)
Nodal force applied on the FEA model
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The Coil tube design Coil dimension 90mm thick
by 180mm long
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with tube and end plate thickness at 25mm and
inner tube at 12mm thick
Total displacement
Displacement on the coil support tube
Max Y-displacement 0.19mm Max Z-displacement
0.09mm
Max X-stress 100MPa Max Y-stress 47MPa Max
Z-stress 138MPa Max YZ- stress 22MPa
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The half Bobbin design Coil dimension 90mm thk x
180 long
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With Bobbin outer shell and end plate thickness
at 25mm, the inner tube is 12mm thick
Max Y-displacement 0.174mm Max Z-displacement
0.058mm Max X-stress 65MPa Max Y-stress
81MPa Max Z-stress 91MPa Max YZ-stress33MPa
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Cases on new coil size (84 x 210 mm) with the
bobbin Various space distance between the coil
and the coil support tube have been studied in
order to understand the deformation of the coil
support structure
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Full length bobbin design
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100mm
1mm thick fibre glass
Coil size 84 x 210mm, the same nodal force
applied on the coil (force data from Jim)
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Observation of results We believe the Bobbin
Coil support is adequate to sustain the
self-equilibrating axial force of some 223
tonnes during magnet quench. The analysis assumed
the coil pulls the core tube, onto which it is
wound, with it radially under a hoop force. This
is a conservative assumption. We need to check if
this force would cause the epoxy to break. If it
does, the coil will be separated from the metal
core tube and thereby eliminate some of the
radial stresses. This will be looked at in more
detail in our next study